For example, Patent Literature 1 discloses a technology in which signals according to light reception states of respective elements of an element group in which they are arrayed in a two-dimensional shape having functions of both light emission and light reception are sequentially read in a reading period that is set in advance, and on the other hand, the respective elements of the element group are caused to sequentially emit light at display signals of voltages according to video signals transmitted from a partner in a display period that deviates from the reading period.